Colon Cancer: Diagnosis, Treatment and Screening Colonoscopy With Dr Carmen Fong

Colon Cancer: Diagnosis, Treatment and Screening Colonoscopy With Dr Carmen Fong

For decades, colorectal cancer was considered a disease that mainly threatened older generations. But doctors are now facing a disturbing shift: more and more younger adults are being diagnosed with a cancer that many never expected to encounter. A symptom as small as blood in the stool, unexplained weight loss, or a change in bowel habits could be the first warning from the body. Experts warn that ignoring these signs may allow a highly treatable cancer to progress into a life-changing diagnosis.

Colorectal cancer has become one of the most important health concerns in modern medicine, not only because of how common it is, but because of the surprising increase occurring among younger adults. Physicians who specialize in colorectal diseases are seeing more patients under traditional screening ages arriving with symptoms that require urgent investigation. The trend has changed the way doctors approach warning signs, especially symptoms that were once easily dismissed in younger people.

For many years, colorectal cancer was primarily associated with older adults, and routine screening recommendations focused on people around the age of 50 and above. However, medical experts have observed a significant rise in early-onset colorectal cancer, meaning cases diagnosed in people younger than typical screening ages. This shift has created a new challenge: younger individuals and even healthcare providers may overlook symptoms because cancer is not expected at that age.

Doctors now emphasize a simple but powerful message: age does not completely protect anyone from colorectal cancer. While the disease remains more common in older populations, younger people can and do develop it. Recognizing symptoms early has become one of the most important ways to improve survival.

One of the most common reasons patients are referred to colorectal specialists is rectal bleeding. Seeing blood in the stool can be frightening, but many people delay seeking medical attention because they assume it is caused by something harmless, such as hemorrhoids or an anal fissure. In many cases, that assumption may be correct. However, doctors warn that the increasing number of colorectal cancer cases among younger adults means bleeding should never simply be ignored.

Bright red blood in the stool often suggests bleeding from the lower part of the digestive system. While hemorrhoids remain one of the most frequent explanations, physicians increasingly recommend evaluation when bleeding occurs, especially if it is new, persistent, or associated with other symptoms.

Medical professionals explain that patients should not feel embarrassed about discussing bowel changes. The digestive system is part of the body, and symptoms involving stool, bleeding, or bowel movements can provide crucial information about health. Delaying evaluation because of discomfort or embarrassment may allow a serious condition to progress.

A colonoscopy is one of the main tools doctors use to investigate possible colorectal cancer. This procedure allows specialists to examine the inside of the colon and rectum using a flexible camera. Depending on the situation, some patients may also undergo a flexible sigmoidoscopy, which examines the lower portion of the colon.

Another important warning sign is unexplained weight loss. Losing weight without changing diet, exercise habits, or lifestyle can sometimes indicate that something abnormal is happening inside the body. While many conditions can cause weight loss, doctors consider it an important symptom when combined with digestive problems.

Abdominal bloating is another symptom that deserves attention. Persistent bloating, discomfort, or changes in digestion may indicate problems within the gastrointestinal system. These symptoms are not always caused by cancer, but they should be evaluated when they appear alongside other warning signs.

Family history also plays a major role in determining colorectal cancer risk. Doctors are especially concerned when someone has a first-degree relative — a parent, sibling, or child — who has had colorectal cancer. A family history does not guarantee that someone will develop the disease, but it increases awareness and may influence when screening should begin.

Certain medical conditions can also increase risk. Inflammatory bowel diseases such as Crohn’s disease and ulcerative colitis are associated with a higher chance of colorectal cancer because long-term inflammation can damage the lining of the digestive tract.

Another symptom that many people do not recognize is a change in stool shape. Doctors describe narrow or pencil-thin stools as a potential warning sign. The reason is related to anatomy: the colon is essentially a long tube. If a tumor or abnormal growth narrows the passageway, stool may become thinner as it moves through the restricted area.

A person may still be able to have bowel movements, which can make the problem easier to ignore. However, a noticeable and persistent change in stool caliber should be discussed with a healthcare professional.

Colorectal cancer is not a rare disease. In many countries, it ranks among the leading causes of cancer-related deaths. In the United States, it remains one of the most common cancers affecting both men and women. However, experts highlight an important point: colorectal cancer is also one of the cancers where prevention and early detection can make a dramatic difference.

The disease often develops slowly. Many colorectal cancers begin as small growths called polyps. Over time, some polyps can change into cancer. This process provides doctors with an opportunity that does not exist for every cancer: they can identify and remove dangerous growths before they become advanced disease.

This is why screening is so important.

Unlike diagnostic testing, which is performed after symptoms appear, screening is performed when a person feels healthy and has no obvious signs of disease. The goal is prevention or early detection.

Doctors compare screening to fixing a problem before a system breaks completely. Finding a small abnormality early is far easier to manage than waiting until the disease has spread.

When a patient visits a doctor with possible colorectal cancer symptoms, the evaluation begins with a medical history and physical examination. Doctors ask about symptoms, family history, previous illnesses, and risk factors.

A physical examination may include an abdominal examination and a digital rectal examination. Although some patients feel uncomfortable with this part of the exam, doctors consider it an important tool. Certain rectal cancers can be detected through this examination because some tumors are located within reach.

Physicians explain that the discomfort is temporary, but the information gained can be valuable. Similar to listening to the heart or examining the mouth, the rectal examination is simply another part of evaluating the body.

After the initial evaluation, colonoscopy is generally the key diagnostic procedure. During colonoscopy, doctors examine the entire colon, searching for abnormal growths, polyps, or tumors.

One major advantage of colonoscopy is that it can both diagnose and treat. If doctors find polyps during the procedure, they can often remove them immediately. This means colonoscopy is not only looking for cancer — it can sometimes prevent cancer from developing.

Other tests, such as virtual colonoscopy or CT colonography, can create images of the colon, but they do not allow doctors to remove suspicious growths. If abnormalities are found through imaging, a traditional colonoscopy may still be required.

If a suspicious lesion is discovered, doctors perform a biopsy. A small tissue sample is sent to a laboratory where specialists determine whether cancer cells are present.

Once colorectal cancer is confirmed, the next step is staging.

Staging determines whether the cancer is limited to one area or has spread elsewhere in the body. This information is critical because treatment decisions and survival expectations depend heavily on the stage.

Doctors commonly use CT scans of the chest, abdomen, and pelvis to look for evidence of cancer spread. They may also perform blood tests measuring tumor markers such as carcinoembryonic antigen (CEA), which can provide a baseline measurement and help monitor response after treatment.

Stage one and stage two colorectal cancers are generally limited to the colon or nearby structures. In many cases, surgery alone can be curative. Doctors remove the section of colon containing the cancer and reconnect the remaining healthy sections.

For early-stage disease, cure rates can approach very high levels because the cancer has not yet spread. Many patients do not require long-term chemotherapy or radiation after successful surgery.

As colorectal cancer advances, treatment becomes more complex.

Stage three disease typically involves nearby lymph nodes, meaning cancer cells have moved beyond the original tumor area. Stage four disease indicates that cancer has spread to distant organs, such as the liver or lungs.

Patients with advanced disease may require chemotherapy, radiation therapy, targeted treatments, or specialized surgeries depending on the location and extent of cancer.

Rectal cancer often requires a different approach compared with colon cancer. Doctors may use chemotherapy and radiation before surgery to shrink tumors and improve outcomes.

Modern treatment has improved significantly, allowing many patients with advanced disease to receive effective therapies that were not available decades ago.

However, the most powerful tool remains early detection.

For people without symptoms, screening recommendations have changed as doctors respond to rising rates of early-onset colorectal cancer. In the United States, many guidelines now recommend beginning average-risk screening at age 45 rather than waiting until age 50.

The reason is simple: colorectal cancer often starts from small polyps that can be detected and removed before they become dangerous.

A screening colonoscopy with normal results may only need to be repeated every several years, often around every 10 years depending on individual circumstances. People with polyps or increased risk may require more frequent monitoring.

Another screening option is the fecal immunochemical test, commonly known as the FIT test. This test analyzes stool samples for hidden blood that may indicate abnormalities in the colon.

While FIT testing is not identical to colonoscopy, it provides another important screening option, especially for people who may not have access to colonoscopy.

The key message from doctors is not to ignore available screening tools. These tests exist because research has shown they save lives.